Technical Field of the Invention
The present invention relates to cell culture devices and fluidic devices. More specifically, the present invention relates to systems and methods that interconnect cell culture devices and/or fluidic devices by transferring discrete volumes of fluid between devices.
Description of the Prior Art
According to existing approaches, fluidic (microfluidic and/or non-microfluidic) devices are typically interconnected using tubing and valves that connect the output of one device to the input of another. However, the use of tubing and valves presents some disadvantages.
In existing systems, a significant length of tubing is needed to connect two devices, and as such, the tubing may end up with a large quantity of dead volume that cannot be used by the devices. At most, this type of interconnection is effective only where small volumes of fluid need to be transferred between devices. Disadvantageously, the tubing must typically be primed with fluid in a complex and time-consuming set of operations that wastes fluid. Furthermore, after a procedure is completed (e.g., between experiments), the connective tubing must be flushed in another complex set of operations. Alternatively, a large quantity of tubing must be wastefully discarded and replaced before a subsequent procedure can be conducted.
While connecting a small number of devices may be possible with existing systems, it becomes increasingly difficult and complex to connect greater numbers of devices. This is especially the case when the interconnection system must use valves to allow the interconnection system to be configured or modified. More devices require more tubing and valves adding to the complexity and the expense of the system. For example, commercial low-volume selector valves used in such systems are very expensive. In addition, future undefined experiments may require new valve designs and tubing architectures. In general, existing approaches do not scale well for interconnection systems that require multiple replicates that need to be similarly interconnected.
The use of tubing for interconnection also results in a system where chemical signals from the devices may be physically separated at a relatively large distance and may take longer times to travel through the tubing and to arrive at the destination. In devices that are connected in series, with a pump pushing liquid from one end, the fluid pressure in the first device will be significantly higher than in the last device. If pumps are connected between devices to alleviate the aforementioned pressure drop then even small mismatches in the pump flow rates and/or pressure will lead to a volume accumulation and pressure increases that may need to be corrected through pressure relief valves and overflow/supplement reservoirs.
Accordingly, there is a need for an improved system for interconnecting fluidic (microfluidic and/or non-microfluidic) devices.